Fermentation process and microorganism for producing aconitic acid

Abstract

Aconitic acid, an unsaturated tricarboxylic acid, is obtained by fermentation of an aconitic acid-accumulating strain of Aspergillus terreus or Aspergillus itaconicus, under aerobic conditions, in a carbohydrate-containing medium, followed by isolation of the aconitic acid or a salt thereof. A preferred aconitic acid-accumulating microorganism is the strain of Aspergillus terreus which is on deposit in the Culture Collection of the Commonewealth Mycological Institute at Kew, Surrey, United Kingdom, under Accession No. CMI CC 281924.

What is claimed is: 
     
       1. A process for producing aconitic acid or a salt thereof which comprises propagating a microorganism selected from Aspergillus terreus CMI CC 281924 and mutants thereof, under aerobic conditions, in an aqueous fermentations medium containing a carbohydrate and a source of assimilable nitrogen and inorganic salts, until at least about 45 g/liter of aconitic acid has accumulated in the medium. 
     
     
       2. The process according to claim 1, wherein said microorganism is Aspergillus terreus CMI CC 281924. 
     
     
       3. The process according to claim 2, which includes the further step of recovering the aconitic acid or a salt thereof from the medium. 
     
     
       4. A biologically pure culture of a microorganism selected from Aspergillus terreus CMI CC 281924 and mutants thereof, said microorganism being an aconitic acid-accumulating strain when propagated under aerobic conditions, in aqueous fermentation medium containing a carbohydrate and a source of assimilable nitrogen and inorganic salts. 
     
     
       5. A biologically pure culture according to claim 4 wherein said microorganism is Aspergillus terreus CMI CC 281924.